In the field of waste processing, recycling and disposal, organic material disposal is a source of numerous challenges.
Food products difficult due to wide variety of shapes, sizes, textures, variations in density in internal and external regions, and variations in water content. For example, bread products present a particular problem for automated waste disposal due to their low moisture content and constituents which tend to be self-adhesive and jam mechanical devices, unless substantial water is added to the bread shredding process.
Another difficulty in organic waste stream processing is providing a single material handling arrangement which can simultaneously and efficiently handle organic materials as diverse as small, soft tomatoes and large, smooth surfaced watermelons, where watermelons tend to simply “ride” on top of material handling equipment sized to handle smaller organic materials. Similarly, the single mechanical arrangement must be capable of providing a consistent flow of material into the processing equipment to provide for efficient and smooth operation of the downstream organic material reduction equipment and to avoid problems with blockages forming in the equipment. Water may be injected into the organic material to help avoid clogging and to otherwise lubricate and cool components during processing, however, this approach has several disadvantages, including requiring provision of piping and connection to a water source, use of large volumes of water (water which continues to increase in cost and may relatively scarce in some regions), and increasing the volume of processed material ultimately requiring disposal at a time in which the cost per unit volume of waste disposal at commercial and municipal facilities is rapidly rising. Further, even where water may be readily available, its use reduces the breadth of organic materials which may be processed, as some materials are not amenable to addition of water during processing. Moreover, water is a costly resource and its use reduces savings from recycling.
On-site organic material processing also requires a significant investment in personnel training on system operation and associated safety hazards. Personnel costs are further increased by the need to devote a significant amount of employee time to operating and monitoring the processing equipment, as well as performing maintenance such as disassembly of components to clear blockages—activities which inherently carry additional risks of operator injury.
Due to the problems inherent in attempting to process a wide variety of organic materials on-site, on-site organic material processing is rarely economically viable, and often is associated with concomitant issues, such as unpleasant odors from decaying organic material, related health concerns, and creation of undesired pest (inset and/or mammal) attraction and intrusion in either indoor or outdoor storage containers. Accordingly, virtually all processing of organic waste from restaurants, grocery stores, institutional facilities and the like is handled offsite, with only temporary on-site holding of the organic material for pick-up and transport to an off-site processing facility and/or waste disposal unit (such as a landfill, compost facility or waste water treatment plant).
The present invention solves the foregoing and related problems in the prior art by providing a unique combination of components and an operating method to produce a system with several advantages, including: a lack of need for water addition to process organic materials, regardless of their source; the ability to produce a fine particle-size discharge which is readily transferred for storage, off-site transfer, recycling and/or disposal; the ability to substantially reduce the volume of the processed organic material to minimize volume-based storage, transportation hauls and disposal costs; the ability of readily simultaneously handle a large variety of organic material sizes, geometries textures and densities without the need for any machine adjustments; and the ability to operate in a self-contained, fully enclosed, autonomous manner after loading, with minimal operator training requirements and a high degree of operator safety. Further, the system may be provided with automated flow disruption self-diagnosis capabilities and the ability to attempt to self-clear clogs and equipment jams before initiating a protective self-shutdown. The system also provides for sanitary and virtually odor-free storage of the processed organic material until the material is removed for off-site handling. The system of the present invention is further capable of processing very large volumes of organic material in a short period of time (such as may be generated at food processing facilities, restaurants or grocery stores) and do so at relatively low equipment noise levels, thereby minimizing energy consumption and facility environment disturbance.
The present invention combines an organic material delivery hopper, preferably with a preferred geometry which facilitates efficient feeding of the organic material, an auger unit for initial crushing and feed transport of organic materials into a further processing unit, where the auger unit has at least one “floating” end which is free to move in a direction transverse to the longitudinal axis of the auger to aid in break-down of the incoming organic material, the further processing unit comprising a solids pump and organic material reduction device, where the solids pump is preferably a positive displacement twin rotor pump which is capable of transferring both solid and liquid materials received from the floating auger into the reducing unit, and the reducing unit preferably is a macerator capable of receiving the positive pressure organic material flow from the solids pump and reducing the material at high speed and high pressure to a finely-processed flow (preferably using any moisture containing in the organic material to form a slurry) which may be sent under positive pressure to a storage facility, preferably an adjacent storage tank, for holding prior to subsequent withdrawal and further off-site processing. The location of a solids pump before a macerator, contrary to common arrangements with a pump downstream of a organic material shredding device, provides a particularly efficient and compact arrangement of components and the generation of a relatively high velocity and high pressure processed organic material stream being discharged from the macerator.
The system may scaled as desired to match the desired processing capability to the expected amount of organic material requiring disposal. For example, a system generally sufficient to handle the volume of organic material which typically is processed for disposal at a large grocery store may be provided in a single enclosure approximately 8 feet long, 3 feet wide and less than 4 feet tall, coupled with an adjacent fiber-reinforced plastic storage tank to receive the processed organic material. The tank may be located inside or outside of the facility. Such a system configuration minimizes the amount of facility floor space required in the store, while also ensuring a sufficiently low lift-height for loading to minimize the potential for lifting-related injury as the operator loads the hopper.
The system is also preferably designed to have a movable cover, such as a sliding top hatch, which may be opened to load in the organic material to be processed, and fitted with at least one interlock (mechanical or electrical/electronic) which prevents system operation when the movable cover is open. Similar safety interlocks may be provided for removable panels on the system enclosure provided for access to the system components for component servicing. So equipped, all that is required for safe operation of the system is for the operator to drop the organic material into the feed hopper, close the movable cover, and turn the system on to permit the imbedded controller to initiate the organic material processing.
An operating method of the present invention may include the placement of organic material in the hopper above the floating auger. The system is preferably provided with a bar or similar device in an upper region of the hopper on which large but relatively fragile materials such as watermelons may be impacted to fracture the material into large pieces which are less prone to rotate on top of the floating auger without entering the auger's flutes to be pushed into the solids pump.
Following the loading of the hopper, the operator moves the cover into its closed position to enable start-up of the system. The operator selects the appropriate processing commands, which may be as simple as a “start” button, and initiates the processing of the organic material. The system primary components, the floating auger, the solids pump and the macerator are then powered to begin processing the organic material in the hopper. Preferably the hopper auger, pump and macerator components are sized such that the processing of the batch of organic material in the hopper may be accomplished in less than five minutes, minimizing energy consumption and noise generation. It is preferable that the system be configured, for example by suitable programming of an electronic controller, to either shut itself down upon detection of completion of processing of the organic material loaded into the hopper (for example, by use of optical sensors detecting the absence of further processed material flow, current sensors detecting termination of load on the auger, pump and/or macerator indicative of lack of material loading, flow sensors, and the like). It is further preferable that the system be configured to operate for a limited period, such as five minutes, after which the system would shut itself down if not previously shut down upon detection of completed organic material processing.
As a part of the automated processing of the organic material following hopper loading, it is preferred that the system be configured to detect flow disturbances and/or flow blockages, for example by detection of excessive current draw in an electric motor driving one of the auger, pump and/or macerator, and in response to such a flow disruption or blockage to cause at least one of (preferably all of) the auger, pump and/or macerator to reverse direction for a period of time to attempt to self-clear the flow disruption or blockage. Further, it is preferable to have the system configured to determine following the reverse operation to determine whether the flow disruption or blockage has been cleared when operation in the forward processing direction is resumed. If the attempt as self-clearing has not been successful, the system may be programmed to repeat the reversal process one of more times (for example, three times) to again attempt to clear the blockage, as development of the present invention determined that many flow disturbances may be remedied with multiple attempts at self-clearing. In order to protect the system equipment and minimize power use and noise generation, after a final unsuccessful attempt at self-clearing the system may be configured to shut down the organic material processing, preferably with an accompanying signal to the operator that manual intervention and system clearing is needed.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.